People are friends with those who smell the same as themselves, study shows

The journal Science Advances published a study by researchers at the Weizmann Institute of Science in Israel who discovered a previously unknown mechanism of friendship, reports NewScientist. It turns out that we subconsciously smell people when we first meet and are more likely to become friends with those whose body odor is similar to our own. This may explain the feeling that we sometimes experience when meeting a new person - as if we have known each other for a thousand years.

The Israeli researchers wanted to see if this could be due to olfactory reasons: previous studies have shown that humans, like other animals, subconsciously sniff each other when they meet – for example, by bringing their hand to their nose after shaking hands with someone.

Scientists conducted an experiment with 20 pairs of same-sex friends - half of them women, half men - who said they became friends from the first meeting. Participants' T-shirts were sniffed with an electronic nose, a device that captures the chemical components of odors. The analysis showed that pairs of friends had more similar body odors than pairs formed by random shuffling of the participants.

The results were confirmed by 25 people in the role of experts who independently sniffed the participants' T-shirts and also found that friends, unlike random couples, smelled similar.

In the third phase of the experiment, the scientists introduced each other to 17 people who had never met before, and again forced the electronic nose to analyze the smell of their bodies. The results were similar: those who had a similar smell admitted that during communication they felt a friendly disposition towards each other.

Earlier research has shown that we tend to befriend those who are similar in age, ethnicity, education, religion, appearance, and personal values to ours. When it comes to smell, we show affinity with other mammals, who use their sense of smell to determine who is their friend and who is their foe. Like dogs sniffing each other's bottoms when they meet on the street.

Curiously, other studies have shown that heterosexual people are attracted to members of the opposite sex who smell differently. This may be due to the fact that smell is associated with genes responsible for the functioning of the immune system, and mating with the owner of a different set of genes means offspring with a stronger immune system.